ftracetest: Add instance created, delete, read and enable event test

Add a new ftrace test that creates three threads. One that creates and
removes an ftrace instance, one that reads the instance, and one that enables
and disables events in the instance. This is a stress test for accessing and
removing instances at the same time.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

tools/testing/selftests/ftrace/test.d/instances/instance-event.tc

+#!/bin/sh
+# description: Test creation and deletion of trace instances while setting an event
+
+if [ ! -d instances ] ; then
+    echo "no instance directory with this kernel"
+    exit_unsupported;
+fi
+
+fail() { # mesg
+    rmdir foo 2>/dev/null
+    echo $1
+    set -e
+    exit $FAIL
+}
+
+cd instances
+
+# we don't want to fail on error
+set +e
+
+mkdir x
+rmdir x
+result=$?
+
+if [ $result -ne 0 ]; then
+    echo "instance rmdir not supported"
+    exit_unsupported
+fi
+
+instance_slam() {
+        while :; do
+                mkdir foo 2> /dev/null
+                rmdir foo 2> /dev/null
+        done
+}
+
+instance_read() {
+        while :; do
+                cat foo/trace 1> /dev/null 2>&1
+        done
+}
+
+instance_set() {
+        while :; do
+                echo 1 > foo/events/sched/sched_switch
+        done 2> /dev/null
+}
+
+instance_slam &
+p1=$!
+echo $p1
+
+instance_set &
+p2=$!
+echo $p2
+
+instance_read &
+p3=$!
+echo $p3
+
+sleep 1
+
+kill -1 $p3
+kill -1 $p2
+kill -1 $p1
+
+echo "Wait for processes to finish"
+wait $p1 $p2 $p3
+echo "all processes finished, wait for cleanup"
+sleep 1
+
+mkdir foo
+ls foo > /dev/null
+rmdir foo
+if [ -d foo ]; then
+        fail "foo still exists"
+fi
+exit 0
+
+
+
+
+instance_slam() {
+    while :; do
+	mkdir x
+	mkdir y
+	mkdir z
+	rmdir x
+	rmdir y
+	rmdir z
+    done 2>/dev/null
+}
+
+instance_slam &
+x=`jobs -l`
+p1=`echo $x | cut -d' ' -f2`
+echo $p1
+
+instance_slam &
+x=`jobs -l | tail -1`
+p2=`echo $x | cut -d' ' -f2`
+echo $p2
+
+instance_slam &
+x=`jobs -l | tail -1`
+p3=`echo $x | cut -d' ' -f2`
+echo $p3
+
+instance_slam &
+x=`jobs -l | tail -1`
+p4=`echo $x | cut -d' ' -f2`
+echo $p4
+
+instance_slam &
+x=`jobs -l | tail -1`
+p5=`echo $x | cut -d' ' -f2`
+echo $p5
+
+ls -lR >/dev/null
+sleep 1
+
+kill -1 $p1
+kill -1 $p2
+kill -1 $p3
+kill -1 $p4
+kill -1 $p5
+
+echo "Wait for processes to finish"
+wait $p1 $p2 $p3 $p4 $p5
+echo "all processes finished, wait for cleanup"
+
+mkdir x y z
+ls x y z
+rmdir x y z
+for d in x y z; do
+        if [ -d $d ]; then
+                fail "instance $d still exists"
+        fi
+done
+
+set -e
+
+exit 0